Bring the maximum power out of your exhaust system with the MACH Force-Xp secondary muffler bypass for the 2012-2014 Porsche 911 Carrera S (991) with H6-3.8L engine. These muffler bypass pipes are used to remove the secondary mufflers that are tucked up in the rear quarter panels reducing weight and improving performance. The muffler bypass pipes are straight through eliminating any muffler packing or baffling.